[newbie] guess need more suggestions

[Pliler Main Unit]

HI,
Here is brief desc of my problem the past 3 days or so.
I installed 5.3 a week ago today, at that time I did not
have nor configure a modem during setup.
I now have an external serial port (com2) modem, and
can't get it to be recognized in spite on DAN, and GILBERT'S
very much appreciated suggestions.
MY question now, is can I re- installl over the old installation
and have during set up the modem configured?
Thanks,

Will Pliler